Large jointer planer combo tables not flat, looking for suggestions

[Darcy Warner]

That’s a shame, I have checked mine and another friend’s Minimax machines and anywhere on the table I can trap a .001” feeler gauge.

I have a Jet cast iron router table, all of those type of tables looked like they were out if the same factory. The table has about a .012” crown to it, it’s offensively out of flat to me. Called the company and they told me it’s acceptable based on their tolerances. ‘Good enough for woodworking’ is the comment that stood out.

It’s not any harder to grind something flat than it is to grind something out if flat, it’s just that ‘good enough woodworking’ gives certain manufacturers the excuse to pass off stuff that should be reworked.

The only way you get bad results like that is crappy set ups/fixtures or just worn out machines.

I believe a lot of old American blanchard's have ended up overseas

[Derek Arita]

Derek, did your tables stay flat after grinding? I really don't won't to return both of them because of the effort that takes. This is my personal shop and it's in my backyard.

Josh, so far it's been about 6 to 10 years and all is well. I'd hoped for flatter after grinding, but what they did made all the difference. Depending on where you are, you could probably find a cheaper shop than I found. I really should have returned the MM J/P, but the back and forth with MM took so long, that I was just fed up dealing with it. That said, after all I went thru with this machine, the $800 was worth it. The lesson for me was, don't buy a major machine without being able to check table tops first.

[Josh vincze]

Derek, Without spending 10k+ what manufacturer would you recommend outside of mm and hammer.

[Derek Arita]

Josh, I wish I could make a good recommendation, but I'm a hobby woodworker, always worked out of my garage and only have direct experience with MM. I've read a lot of good things about the Hammer J/Ps, but along with the bad, I've also read good about MM. I have a feeling, the more you pay, the more control you'll have over what you actually receive.
If I were buying my J/P again, I'd ask MM to tell me the exact flatness of the tables that they are sending me. If they can't do that, I'd move on, cuz when it comes to jointers and planers, table flatness is essential. If you're buying from a local retailer, I'd insist on being able to measure flatness before purchasing. Pay no attention if they tell you the tables are within tolerance of .01", which is what I was told, because .01 is way too much, no matter how well the tables are adjusted.
I have no doubt that J/Ps from Jet to Felder will do the job well, as long as the tables are flat or at least within .005. Good luck.

[Brian Holcombe]

Derek, Without spending 10k+ what manufacturer would you recommend outside of mm and hammer.

Buy used. This is not without its own set of aggravations but often enough you get a much better machine for the money and have the ability to inspect the actual machine you will be receiving.

Typically when I buy used I budget in the cost of making things to the spec I want them to be, so If I want the tables flat I assume the amount part of the cost of the machine.

[Josh vincze]

Anyone have any experience with Robland? From what I've read this would be a down grade for me but I would be able to drive to their North Carolina headquarters and possibly put my hands on the machine before purchasing.
This would not be my ideal direction seeing how it would take more effort but maybe with compelling arguments it's a possibility.

[Mike Kees]

I agree completely with Brian. In fact in my shop,there are currently only two machines that I purchased new out of thirteen total.

[Derek Arita]

Used is a great option, as you can get more for your $ and take all the measurements you desire. That said, if that's not an option for you, then yes, Ive heard good things about Robland.
if you can put hands on the machine you're thinking about purchasing, its ideal. Just make sure you take your measuring tools with you, don't hold back and don't let the salesperson convince you out of what you know and want.

[Alex Zeller]

Here's my take. If you are not happy you never will be. Short of having the tables remachined it's always going to be in your mind. If it didn't bother you then you wouldn't think twice about it. I would suggest sending them both back unless the company is willing to go beyond what they have done now and possibly having them machined. Are there any local places that sell what you want? If so I would pay the extra they may charge so they can get a machine in and you can inspect it before paying. I would be upfront with them and what you expect.

[Jacob Reverb]

I wonder how flat they would stay even if they were re-machined.

+1

I also wonder how much the measurements/shapes of the castings continuously change due to temperature changes in the shop, Δt values and differential thermal expansion within the castings.


With all the talk you hear around here of feeler gages, mils, tenths, interferometers and Planck lengths, it's a wonder any wood ever gets cut.


Just sayin'.

[Brian Holcombe]

+1

I also wonder how much the measurements/shapes of the castings continuously change due to temperature changes in the shop, Δt values and differential thermal expansion within the castings.


With all the talk you hear around here of feeler gages, mils, tenths, interferometers and Planck lengths, it's a wonder any wood ever gets cut.


Just sayin'.

Unless it's a complete disaster of a casting then change in temperature is not going to affect the flatness so much. Yes, if you're scraping in a machine table, then you'll want the temperature consistent. But in a realistic use scenario a bit of temperature change isn't going to be so drastic an effect that one should not consider flattening a table considerably out of flat.

No need to make the great into the enemy of the good. A .001" change in flatness over the course of temperature change isn't the reason why you stick with a .010" out of flat table.

I like to consider the fact that having a machine which provides repeatable results is a time saver in my shop. Putting the effort in to ensure that it is accurate is relatively painless by comparison to fighting joinery/glue ups.

[Derek Arita]

I introduce enough human error all by myself. I always try to reduce error coming from my machines, whenever possible. I always think about the 5-cut method as an example of how a tiny error can result in a huge error in the end. I can't predict what the castings will do over time, but I can look for the best starting point as possible.

[Jacob Reverb]

I guess I never broke out the feeler gages with my jointer. I put a Starrett 24" combo square blade onto the tables of my PM jointer before accepting delivery and unloading it off the lift gate, set it up, tried it – it worked – and called it good. Let's not try to make this into a false dichotomy between those who hate accuracy/measurement/minimizing error and those who don't. Everybody settles. The question is merely, where?

If a 10-mil belly in the middle of a 4' outfeed table is unacceptable, then jointing with nothing more than a Stanley #7 must introduce astronomical errors by comparison. Yet somehow, it works – and has for centuries. If a tool does what I want it to do, that's good enough for me. Life's too short. YMMV.

Good luck with whatever you decide to do, Josh.

[Brian Holcombe]

In a time period where one can purchase a granite plate 18x24 flat to three one hundredths of a thousandth for a couple hundred dollars, I can’t see where a precision ground table can’t be made near perfectly flat. The difference is that one set of customers will definitely reject poor quality results and in the other case the customer most likely will simply let it slide.

The point at which to settle, in my opinion, is the point at which the level of surface flatness or similar metric no longer has a meaningful influence on the work. That number is closer to .001” than .010” in my experience.

[David Kumm]

.010 dip on either end isn't a deal breaker. A hump is worse and either across the width near the head on the outfeed is really bad. Given that the tables are relatively small, the standard should be better but we should also ask what that standard is before buying. Knowing the possible error at least allows for an email history of expectations between buyer and seller. I rejected a 20" , 8' Porter with recently ground tables that were .008 off. I figured if newly surfaced tables weren't flat, it was better to avoid. Seller actually agreed. Dave